Mechanism for lining shells

ABSTRACT

Mechanism and method for lining a series of pivotally interconnected shells each having bottom, side, and recessed end walls utilizes means for imparting movement to said shells along a predetermined path in end to end relation, means for moving a sheet of stretchable material alongside said series of shells in synchronism therewith, force applying means for urging said sheet of material into close frictional contact with the edges of the side walls of said shells, a pair of endless elements having their working reaches disposed alongside said shells and sheet and engagable with said sheet to urge portions thereof between the side walls of the shells into snug contact with the recessed ends of the shells, and vacuum means for drawing the sheet into flat face contacting relation with the bottom, sides and ends of the interior surfaces of said shells.

United States Patent Calvert Inventor:

Assignee:

Filed:

Appl. No.:

MECHANISM FOR LINING SHELLS Rodney K. Calvert, Dunwoody, Ga.

The Mead Corporation, Dayton,

Ohio

Sept. 15, 1970 US. Cl. ..425/383, 425/388, 425/453 Int. Cl ..B29c 17/02 Field of Search ..l8/l9 R, 19 F, 19 N, 19 BC,

l8/DlG. 48, DIG. 53, DlG. 6, 4 C, 5 A, 4F,

References Cited UNITED STATES PATENTS 11/1954 ll/l967 7/1963 2/1972 2/1969 Primary ExaminerJ. Spencer Overholser Assistant Examiner-David S. Safran Attorney-Walter M. Rodgers ABSTRACT Mechanism and method for lining a series of pivotally interconnected shells each having bottom, side, and recessed end walls utilizes means for imparting movement to said shells along a predetermined path in end to end relation, means for moving a sheet of stretchable material alongside said series of shells in synchronism therewith, force applying means for urging said sheet of material into close frictional contact with the edges of the side walls of said shells, a pair of endless elements having their working reaches disposed alongside said shells and sheet and engagable with said sheet to urge portions thereof between the side walls of the shells into snug contact with the recessed ends of the shells, and vacuum means for drawing the sheet into flat face contacting relation with the bottom, sides and ends of the interior surfaces of said shells.

7 Claims, 7 Drawing Figures PATENTEDFEBHIBYS 7 5,

SHEET 1 [IF I 4 FIG I INVENTQR. RODNEY K. CALVERT L BY ATTORNEY PATENTED FEB] 31975 SHEET 2 BF 4 FIG. 2

FIG. 3

' INVENTOR. RODNEY K. CALVERT Arum 5r FIG. 4-

PATENTEDFEB 1 31915 3; 71 6,321

SHEET 3 B? FIG. 5

INVENTOR. RODNEY K. CALVERT MECHANISM FOR LINING SHELLS In order to provide secure contact between a sheet of material and the recessed end edges of a series of pivotally interconnected shells, a pair of flexible endless elements are disposed with their working reaches in engagement with said sheet and arranged so as to urge intermediate portions of said sheet into secure contact with the recessed end edges of the shells. The working reaches of the endless elements are arranged to move in divergent relationship to each other and in synchronism with the series of shells and sheet so as to impart desired manipulative operations to said sheet as a preliminary step to the application of vacuum pressure inside of the shells for the purpose of drawing the sheet into snug contact with the interior surfaces of the shells.

For a better understanding of the invention, reference may be had to the following detailed description taken in conjunction with the accompanying drawings in which FIG. 1 is a plane view of a machine to which the invention is applicable;

FIG. 2 is a profile view taken along the line designated 2 2 in FIG. 1;

FIG. 3 is an enlarged plan view of a portion of the structure shown in FIG. 1 and which comprises endless elements arranged to urge a sheet of material into engagement with the shells shown in profile in FIG. 2;

FIG. 4 is a cross sectional view of one of the shells taken along the line designated 4 4 in FIG. 2;

FIG. 5 is a cross sectional view taken along the line designated 5 5 in FIG. 1;

FIG. 6 is a perspective view of a finished package formed by the machine shown in FIG. 1; and in which FIG. 7 is a view generally similar to FIG. 5 but with parts of FIG. 5 removed and with other parts shown substantially enlarged for clarity.

In the drawings and particularly with references to FIG. 1, a plurality of primary packages such as cans C are fed into the left hand end of the machine in the direction of the arrow I on conveyor 2. These cans are separated into two rows of cans and their rate of infeed is metered by rotatable star wheels 3 and 4 which function in known manner. Acceleration of the cans in the two separated rows is achieved by the rotatable ac celerating devices 5 and 6 which function in a manner disclosed more specifically in U. S. Pat. No. 3,521,737 issued July 28, 1970.

The cans C proceed in groups such for example as in two rows of three each from left to right as represented at G1 and G2. One row of cans such as that designated as C1, C2 and C3 is received within a half-section formed by one of the pivotally interconnected shells such as that designated in FIG. 1 by the numeral 7. The half-sections formed within the shells are formed from the stretchable film F which is urged into the hollow shell 7 and held in lining relationship therein by vacuum means imparted from a rotatable manifold 8 through a series of flexible conduits such as are designated by the numerals 9, l0 and 11. A different one of the conduits interconnects the manifold 8 and each one of the shells. For example shell 7 is interconnected with manifold 8 via conduit 10. A source of vacuum (not shown) thus imparts suction pressure to the interior of shell 7 through manifold 8 and line 10.

The half-sections formed of film F within each of the shells such as 7 cooperate with a corresponding halfsection formed on the opposite side of the machine and arranged to envelop the articles such as C4, C5 and C6.

The chain of shells which forms the half-sections which envelop the cans such as C4, C5 and C6 are not shown in the drawings for the sake of clarity and simplicity, it being understood that the film Fl cooperates with a series of shells (not shown) to form a series of interconnected half-sections which are secured to the corresponding haIf-section on the other side of the machine to form the finished package P as shown schematically in FIG. 6, all as more specifically disclosed in U. S. Pat. applications Ser. No. 31,688 filed Apr. 24, 1970, now U.S. Pat. No. 3,629,990, and Ser. No. 31,687 also filed Apr. 24, 1970, now U.S. Pat. No. 3,642,414.

Since the two sides of the machine are substantially identical, a description of that portion of the machine which is utilized to line the half shell such as 7 and the associated shells is here described in detail.

Prior to lining the shells, the film such as F is heated as it approaches the side edges such as 12 and 13 of side walls 14 and 15 of the shells such as l6, 17, 18 and the like, the bottom wall of each shell being designated by the numeral 19.

For the purpose of urging and holding the film into secure contact with the edges 12 and 13 of the shells, an endless flexible element 20 is mounted on rollers 21 and 22 one of which is an idler roller and the other of which is a driving roller.

Thus with the film such as F in engagement with the edges such as 12 and 13 of side walls 14 and 15, the film must be forced into snug and secure engagement with the recessed end walls such as 23 and 24 of the aligned shells. Toward this end, the structure as shown in FIGS. 2, 3, 5 and 7 is employed. More specifically, a pair of flexible endless elements 25 and 26 are mounted on rollers 27 and 28, one roller being a driven roller and the other being an idler roller. As is best shown in FIG. 3 endless elements 25 and 26 are urged transversely by fixed pressure plate 29 which is adjustably mounted by means of bolts 30 and 31. As is best shown in FIG. 2 the endless elements 25 and 26 diverge from each other as particular parts thereof move from right to left at the entry end of the working reaches of the endless elements as indicated at 25b and 26b and converge at the exit end of the working reaches as Indicated at 25C and 26C. At the point designated by section line 5 5 in FIG. 1, the endless elements 25 and 26 occupy the positions depicted in FIG. 5 i. e. in snug engagement with the recessed ends 23 of the bucket near the section designated 5 5 in FIG. 1. When in this position, of course the film F is held in secure engagement with the edges 12 and 13 of the side walls 15 and 14 by the endless element 20 as best shown in FIGS. 1, 5 and 7 which in turn are disposed about center pressures plates 20A and 20B. Flexible endless element 25 is held in the position shown, for example, in FIG. 5 by the pressure plate means 29 while the endless element 26 is supported and held in the position shown by pressure plate means 29A. These pressure plates are supported in any suitable manner as by the bolts 30 and 32 which in turn are supported by angles 33 and 34 mounted by bolts 35 and 36 to frame elements 37 and 38 respectively. Track means 39 and 40 are mounted on support elements 37 and 38 respectively and cooperate with rollers such as 41 and 42 rotatably mounted on each of the half shells to determine the path of travel of the chain of shells. The pressure applying elements 20, 25 and 26 are urged toward the right and into snug engagement with the sides and ends of each shell by means of the flexible hollow pneumatic device such as 43 which when internal pressure is applied thereto drives the bracket 44 toward the right by virtue of a lost motion slot 45 formed in the brackets 33 and 34 to cause the pressure applying elements such as 20, 25 and 26 to force the film into the position shown in FIG. 5.

Once the film is forced into engagement with the edges of the side and end walls, a vacuum pressure is applied within the shell to force the film into snug flat face contacting relation with the inside surfaces of the bottom, side, and end walls. Thereafter each half-section thus formed is moved into enveloping relation with the cans such as C1, C2 and C3. Continued movement brings the half-sections on one side of the machine into cooperative engagement with the corresponding halfsections on the other side of the machine. Thereafter heat is applied to seal these sections together by the device generally designated by the numeral 46 in FIG. 1. The package with its associated half-sections secured together is then passed through a heating tunnel generally designated by the numeral 47 where appropriate shrinkage is imparted to the half-sections to result in a finished package such as is indicated at P in FIG. 6.

As is best shown in FIG. 7 the endless elements 25 and 26 constitute chains such as 48 and 49 together with sponge-like cushioned elements 50 and 51. If desired, the endless elements 25 and 26 each could comprise a chain with a continuous series of segments secured to each chain some of which could be formed of metal.

Since a major portion of the stress on the film such as F and F1 is applied in the region of the corners 52, 53, 54 and 55 of the package, it is desireable to arrange the mechanism so that the part of the film which ultimately becomes the corners of the package is not unduly stressed and stretched during the lining operation described above. Toward this end and according to a feature of the invention, the endless elements 25 and 26 serve to cool those regions of the film F and F1 upon contact due to the fact that the return reaches such as 25A of these elements are disposed outside the region of the heated portion of the machine and in such ambient conditions tend to cool. Thus cooling action is imparted to the portions of the film which are contacted by the endless elements 25 and 26 and this cooling action tends to prevent those portions from stretching. The sponge-like elements 50 and 51 are yieldable and impart a gentle force whereby the film is stretched into the recessedends of the shells and due to the divergent paths of travel of the endless elements 25 and 26 as best shown in FIG. 2, the film is contacted near its center line initially and as the stretching operation progresses, the divergent endless elements 25 and 26 swing the portions of the film disposed between the pressure applying elements 20 and the endless elements 25 and 26 about the edges 12 and 13 of the side walls and 14 of the shells. Thus it is apparent that the portion of the film to which the major stretching action is imparted is the center portion i. e. that part designated for example in FIG. 5 by the numeral F2 which is disposed between the endless elements 25 and 26. Stretching and thinning of this portion of the half-section does not impair the strength of the finished package because this portion of the film such as that designated F2 ultimately becomes the side walls of the carton such as are designed in FIG 6 by the numerals 56 and 57 leaving the corners relatively thick and strong where strength in needed. Thus according to the invention, film such as F and F1 is heated and stretched to form half-sections which line the pivotally aligned shells and which stretching is specifically accomplished so as to facilitate formation of the package and to perform the stretching so that the ultimate package is strong where strength is needed.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

I. Mechanism for lining a series of pivotally interconnected shells each having bottom side and recessed end walls with stretchable sheet material comprising means for imparting movement to said shells along a predetermined path in end to end relation, track means for engaging said shells and for limiting movement thereof in a direction transverse to said path, means for moving a sheet of said material alongside said series of shells in synchronism therewith, endless flexible force applying elements disposed alongside said sheet of material and movable in synchronism therewith and independently of said shells for holding said sheet in close contact with the edges of said side walls of said shells, flexible endless elongated means movable with said shells and sheet and arranged with its working reach disposed in generally parallel relation to said path to engage directly and urge portions of said sheet into snug engagement with said recessed end walls, and pressure plate means in engagement with said endless elongated means for holding said flexible endless elongated means in position.

2. Mechanism according to claim I wherein said flexible endless elongated means comprises a pair of endless elements disposed alongside each other.

3. Mechanism according to claim 2 wherein the working reaches of said endless elements move along divergent paths near the entry portions thereof.

4. Mechanism according to claim 1 wherein said flexible endless elongated means is disposed to engage portions of said sheet which are between the parts thereof which are held in engagement with said edges of said side walls.

5. Mechanism according to claim 1 wherein said sheet is heated to a temperature substantially above ambient temperature and wherein the return reach of said flexible endless elongated means is exposed to ambient air of substantially lower temperature than said sheet whereby substantial cooling thereof occurs in said return reach.

6. Mechanism for lining a series of pivotally interconnected shells each having bottom side and recessed end walls with stretchable sheet material comprising means for imparting movement to said shells along a predetermined path in end to end relation, track means for engaging said shells and for limiting movement thereof in a direction transverse to said path, means for moving a sheet of said material alongside said series of shells in synchronism therewith, force applying structure disposed alongside said sheet of material and movable in synchronism therewith for holding said sheet in close contact with the edges of said side walls of said shells, and flexible endless elongated means movable with said shells and sheet and disposed to engage andurge portions of said sheet into snug engagement with said recessed end walls, said flexible endless elongated means comprising a pair of endless elements disposed alongside each other and arranged to engage parts of said sheet which are disposed at or near the junctions between said side walls and said bottom of each of said shells upon completion of a shell lining operation.

7. Mechanism for lining a series of pivotally interconnected shells each having bottom side and recessed end walls with stretchable sheet material comprising means for imparting movement to said shells along a predetermined path in end to end relation, track means for engaging said shells and for limiting movement thereof in a direction transverse to said path, means for moving a sheet of said material alongside said series of shells in synchronism therewith, force applying structure disposed alongside said sheet of material and movable in synchronism therewith for holding said sheet in close contact with the edges of said side walls of said shells, and flexible endless elongated means movable in synchronism with said shells and sheet and disposed to engage and urge portions of said sheet into snug engagement with said recessed end walls, said flexible endless elongated means comprising a pair of endless elements disposed alongside each other and said endless elements each including a cushioned high friction sheet engaging surface which tends to cause substantially greater stretching of the part of said sheet which coincides with the bottom of each shell than the parts thereof which coincide with the side walls thereof upon completion of a lining operation. 

1. Mechanism for lining a series of pivotally interconnected shells each having bottom side and recessed end walls with stretchable sheet material comprising means for imparting movement to said shells along a predetermined path in end to end relation, track means for engaging said shells and for limiting movement thereof in a direction transverse to said path, means for moving a sheet of said material alongside said series of shells in synchronism therewith, endless flexible force applying elements disposed alongside said sheet of material and movable in synchronism therewith and independently of said shells for holding said sheet in close contact with the edges of said side walls of said shells, flexible endless elongated means movable with said shells and sheet and arranged with its working reach disposed in generally parallel relation to said path to engage directly and urge portions of said sheet into snug engagement with said recessed end walls, and pressure plate means in engagement with said endless elongated means for holding said flexible endless elongated means in position.
 1. Mechanism for lining a series of pivotally interconnected shells each having bottom side and recessed end walls with stretchable sheet material comprising means for imparting movement to said shells along a predetermined path in end to end relation, track means for engaging said shells and for limiting movement thereof in a direction transverse to said path, means for moving a sheet of said material alongside said series of shells in synchronism therewith, endless flexible force applying elements disposed alongside said sheet of material and movable in synchronism therewith and independently of said shells for holding said sheet in close contact with the edges of said side walls of said shells, flexible endless elongated means movable with said shells and sheet and arranged with its working reach disposed in generally parallel relation to said path to engage directly and urge portions of said sheet into snug engagement with said recessed end walls, and pressure plate means in engagement with said endless elongated means for holding said flexible endless elongated means in position.
 2. Mechanism according to claim 1 wherein said flexible endless elongated means comprises a pair of endless elements disposed alongside each other.
 3. Mechanism according to claim 2 wherein the working reaches of said endless elements move along divergent paths near the entry portions thereof.
 4. Mechanism according to claim 1 wherein said flexible endless elongated means is disposed to engage portions of said sheet which are between the parts thereof which are held in engagement with said edges of said side walls.
 5. Mechanism according to claim 1 wherein said sheet is heated to a temperature substantially above ambient temperature and wherein the return reach of said flexible endless elongated means is exposed to ambient air of substantially lower temperature than said sheet whereby substantial cooling thereof occurs in said return reach.
 6. Mechanism for lining a series of pivotally interconnected shells each having bottom side and recessed end walls with stretchable sheet material comprising means for imparting movement to said shells along a predetermined path in end to end relation, track means for engaging said shells and for limiting movement thereof in a direction transverse to said path, means for moving a sheet of said material alongside said series of shells in synchronism therewith, force applying structure disposed alongside said sheet of material and movable in synchronism therewith for holding said sheet in close contact with the edges of said side walls of said shells, and flexible endless elongated means movable with said shells and sheet and disposed to engage and urge portions of said sheet into snug engagement with said recessed end walls, said flexible endless elongated means comprising a pair of endless elements disposed alongside each other and arranged to engage parts of said sheet which are disposed at or near the junctions between said side walls and said bottom of each of said shells upon completion of a shell lining operation. 